Title-backed photosensitive microfiche

ABSTRACT

A thin layer containing a suitable pigment in a polymeric binder is striped on a film base to provide, in the header region of a microfiche a surface that is receptive of titles (e.g., written, printed or typed images), makes photographically recorded images eyeball readable, is translucent to visible light, yet transparent to photographically active radiation (i.e., radiation capable of being detected after processing using conventional photosensitive materials and processes) thereby permitting conventional reproduction of the entire microfiche including the header region.

United States Patent Hunter 51 Mar. 7, 1972 [54] TlTLE-BACKED PHOTOSENSITIVE 3,148,064 9/1964 Rauner et al. ..96/9l MICROFlCl-[E 2,709,655 5/1955 Frederick ..96/75 2,908,572 10 1959 S h t l ..96 75 [72] lnventor: Clarence S. Hunter, Rochester, N.Y. c e a I X [73] Assignee: Eastman Kodak Company, Rochester, OTHER PUBLICATIONS Microphotography Fundamentals and Applications," SPSE TR835.59 1968 165. 22 Fld: Fb.91970 1 l e e Unconventional Photography Systems, SPSE, 2nd Symp., [21] Appl. No.2 9,586 [967, 6.9,

Primary Examiner-Charles L. Bowers, Jr. 5 .S. Cl I 2] u 96,67 96,75 0 2 AttorneyWalter O. l-lodsdon and Arthur L. Guard [51] int. Cl ..G03c 1/52, G03c 1/00, G03c ]/78 58 Field of Search ..96/75,9l, 87,67, 115 [571 ABSTRACT A thin layer containing a suitable pigment in a polymeric [56] Ree'mces C'ted binder is striped on a film base to provide, in the header region UNITED STATES PATENTS of a microfiche a surface that is receptive of titles (e.g., written, printed or typed images), makes photographically 3,447,947 9 Abbott 6 -.96/75 UX recorded images eyeball readable, is translucent to visible 2 10/ 1969 Abbott et al. ....96/75 X light, yet transparent to photographicaliy active radiation (i.e., 3,223,769 H1966 Workman 96/75 X radiation capable of being detected after processing using 3,284,201 11/1966 M6115 ct 75 conventional photosensitive materials and processes) thereby 3,539,378 11/1 h p r et al. 96/87 X permitting conventional reproduction of the entire microfiche 3,136,637 6/1964 Larson ..96/ including the header region, 2,603,564 7/1952 Maxcy ....96/9l R 2,999,016 9/1961 Beeber et al. ..96/87 X 6 Claims, 3 Drawing Figures /2 VOL. 7, PAGES 25 W W W W W M W W W M W W /0 i i j FILM BASE Q- BM 20 EMUL s/o/v \QFD/AZO EMULSION ,j-F/LM BASE TITLE-BACKED PHOTOSENSITIVE MICROFICIIE FIELD OF THE INVENTION The present invention relates to an improved microfiche and more particularly to such a microfiche having an easily reproducible translucent stripe capable of receiving eyeball readable print or information or permitting eyeball reading of photographically incorporated identifiers or legends in the area of said translucent stripe in the header area.

PRIOR ART A perplexing problem in the microfiche art has been that of providing an eyeball readable title or identification system which, in addition to being easily seen and read on the original microfiche is similarly available for identification on subsequent copies of the diazo film made using a conventional reproductive process.

Although a number of systems including microfilm jacket headers and a product known as the Title Diazo Microfiche supplied by Technifax Inc. have been proposed to solve this problem, none of them has proven to be entirely satisfactory since although like the products just mentioned they are suitable for the identification of the original microfiche, the header portion of the latter product does not reproduce at all and that of the former reproduces only with some difficulty when conventional diazo processing is used.

It is therefore an object of the present invention to provide an improved microfiche which has a conventionally reproducible header area, and is receptive to eyeball readable identifiers.

DESCRIPTION OF DRAWINGS Other objects and advantages of the present invention will be made obvious when the following description is considered in connection with the accompanying drawing of which:

FIG. 1 is a front view of a microfiche of the type described herein;

FIG. 2 is a cross-sectional view of the header portion of a conventional microfiche of the type shown in FIG. 1;

FIG. 3 is a cross-sectional view of the header portion of a preferred embodiment of the microfiche of the present invention.

SUMMARY OF THE INVENTION According to the present invention, there is provided a diazo microfiche having a translucent header stripe capable of receiving eyeball readable print and also making identifiers in the photographic emulsion in the header region readable while being transparent to photographically active light and therefore completely reproducible using conventional diazo reproductive techniques.

More particularly, the invention provides a microfiche having a thin layer comprising a suitable pigment having a refractive index between about 1.6 and 2.1 in a polymeric binder striped in the header region of a diazo microfiche to provide a surface that is receptive of titles or identifiers (e.g., typed, printed or written images), is translucent to visible light, yet photographically transparent thereby permitting conventional reproduction of the entire microfiche including the header region and the identifiers included thereon.

DETAILED DESCRIPTION OF THE INVENTION As shown in FIG. 1, a conventional microfiche 10 suitable for use in accordance with this invention is divided into two areas, the top or header section 12 and the lower or information bearing section 14 which contains the actual material being stored in page or other form 16 on the microfiche. Identification of the microfiche is conventionally made, as already described, by entering eyeball readable information 18 in one fashion or another, for example by typing or photographic reproduction in the header region 12.

The diazo reproduction problems of the prior art discussed above are apparently due largely to the difficulty in finding a suitable combination of materials which are sufficiently opaque to visible light, i.e., provide just the right degree of translucency that printed or typed lettering imposed thereon or reproduced in the fiche can be read with the naked eye while being completely, or at least nearly so, transparent to the radiation utilized to reproduce the microfiche.

It has now been discovered that when a thin layer comprising a suitable pigment having a refractive index between about 1.6 and 2.1 in a polymeric binder is coated, preferably on the side of the microfiche base layer opposite that which is coated with the photosensitive diazo emulsion, as described in greater detail below, the header region can be made sufficiently translucent or diffuse to permit the imposition of eyeball readable print thereon while remaining transparent to photoactive radiation so that copies of the original microfiche including the header region and its included identifiers can be made without difficulty.

As shown in FIG. 2, a conventional microfiche comprises a sheet of film base cast, extruded or otherwise formed from a suitable material, e.g., poly(ethylene terephthalate), cellulose acetate, cellulose acetate butyrate, or other polyester, cellulose ester or even polyolefin, polyamide, or polycarbonate materials having a layer of a diazo or silver halide emulsion coated on one side thereof. Any number of sub" or U" coats, bonding layers, antihalation and/or antistatic layers (not shown) may also be applied to provide proper adhesion between the emulsion layer and the film base or to correct other problems which arise in the use of such materials. The point being that in the conventional microfiche only a single face of the microfiche, including the header region, is generally coated with any type of useful or functional layer.

A preferred embodiment of the improved microfiche of the present invention, as shown in cross section in FIG. 3, has, at least in the header region, a second functional layer coated on the surface of the film base sheet opposite that which is coated with the emulsion. The particular location of the pigment and binder may, however, be varied as described below. It is this thin layer of pigment and polymeric binder which provides the properdegree of opacity and diffusion and all but complete transparency to photoactive radiation and imparts the improved reproductive properties already described above.

The thin layer which generally, in the finished microfiche, ranges in thickness from about 0.03 to about 0.20 mil may be applied using conventional roll coating, spraying, flexographic, gravure, or other suitable techniques to deposit a layer of a solution comprising a weight ratio of binder to pigment ranging from about 3:1 to about 1:3 and the balance of the solution being some suitable solvent or mixture of solvents for the polymeric binder. The pigment used as described more fully below, must, according to the method of this invention have a refractive index ranging from about 1.6 to about 2.]. The polymeric binder-pigment solution can be formed using any conventional mixing technique used to prepare coating or spraying solutions of polymers. This list would of course include ball milling, Kady milling, roll milling and dissolving of predispersed pigments in binders.

The particular solvent used will, of course depend upon the particular binder employed and considerations such as compatibility of the solvent with the film base material and the photosensitive emulsion as well as the particular substrate attack characteristics of the solvent on the base material should also be evaluated. Once applied, the solution is dried by evaporation of the solvent using conventional hot air, or other drying techniques to leave a thin layer, i.e., ranging in thickness from about 0.03 mil to about 0.2 mil and preferably between about 0.05 and 0.15 mil comprising from about 20 to about percent by weight of the pigment and from about 80 to about 20 percent by weight of the polymeric binder.

Although according to the preferred embodiment of the invention depicted in FIG. 3, the preferred polymeric pigment layer is coated on the reverse side of the microfiche from that which bears the diazo emulsion, it has been found possible to coat the binder-pigment layer either between the film base and emulsion or over the emulsion at least in the header region of the microfiche. When either of the latter two orientations are utilized, it is of course necessary that the binder, pigments other additives and solvents for the binder be highly compatible so that no loss of physical, or photographic characteristics is encountered.

It should be noted that regardless of the orientation of the binder-pigment layer relative to the film base and emulsion layer that the entire area of the microfiche may be coated with the thin layer of the present invention without any adverse effects being experienced by the total product, however, clearly, economic reasons would seem to dictate that providing such a layer only in the header region would provide the desired improvement while supplying a less expensive product.

The polymeric binder utilized may vary broadly across a wide range of such materials. Normally, all such binder materials which are clear, transparent to photographically active radiation and conventionally used as binders in inking and backing applications are useful in the successful practice of the present invention. This list includes, but is not limited to such materials as: cellulose nitrate, cellulose acetate, cellulose acetate butyrate, acryloids, suitable polyester materials, vinyl resins, rosin and rosin derivatives, shellac, epoxy resins, and necessary additives used to improve dispersion, flow out and adhesion in bonding, and mixtures of the above materials. Specifically preferred for the binder, however, are polyamide resins which generally provide improved adhesion with many of the conventional polyester film base materials. Specifically preferred among the polyamide resins generically described as the condensation products of dimer acids and linear diamines, is the polyamide prepared from the condensation of dilinoleic acid and ethylene diamine marketed by General Mills under the trademark Versamid 940, a solid polyamide resin, amine value 4 mg. KOH/g A.V. 4, melting point 1 C. .soluble in several simple alcohols such as N-propanol and which adheres well to several types of plastic films particularly conventional poly(ethylene terephthalate), modified poly(ethylene terephthalate) materials and polyolefin materials.

Other polyamide resins for flexographic inks which are based on diphenolic acid (DPA) 4,4-bis-(4-hydroxyphenol)- pentanoic acid and which are similarly soluble in simple alcohols to form varnishes may also be used as the binder material.

Although the polymeric binders can be selected to adhere quite readily to most conventional film base material (such as those mentioned above) it may be advisable to apply a U-coat of,.for example thosedescribed in U.S. Pat. No. 3,488,195, when a polyester base such as poly(ethylene terephthalate) is used, and any other number of subbing'or U-coats which improve the adhesion of the binder to the base without affecting the visible light transparency of the header region, or adversely affecting the diazo or silver emulsion which forms the photographic portion of the microfiche may be similarly employed.

The pigmentwhich is dispersed in the polymeric binder must possess a refractive index of between about L6 and 2.1 to provide the required low degree of hiding power. Testing has indicated that pigments within this range while being substantially transparent to photoactive radiation and providing sufficient opacity when present in the binder in concentrations of from about to about 80 percent by weight at the header stripe thicknesses described below, also permit easy eyeball reading of identifiers imposed thereon or incorporated in the photosensitive emulsion to be read thereagainst. Among the pigments falling into thisclassification are BaSO, (known in the art as Baryta), zinc oxide and Lithopone which is chemicallyidentified as ZnS-BaSO, and is well known in the pigment art. Tests using silica as the pigment (index of refraction 1.552) indicate that it is unsuitable in the present application. It therefore appears that the list of suitable pigments is quite limited to those within the specified range of refractive index.

The basic philosophy of the present invention is to achieve controlled hiding by varying pigment concentration and layer thickness to provide the required opacity and diffusion characteristics to permit eyeball reading of the identifiers imposed on the header stripe of the invention or included in the photographic emulsion thereof. This controlled thickness and concentration is achieved by maintaining the opacity or density of the finished stripe as measured on an integrating sphere spectrophotometer at a total optical density of at most about 0.3 and preferably at or below about 0.2.

Quite clearly, the optical density will vary with both the concentration of the pigment in the binder and the thickness of the layer which is applied. When pigment concentrations on the order of those described above are used the desired optical density is achieved using a layer thickness of from about 0.03 to about 0.2 mil. In cases where it is desirable that the header stripe be applied to microfiche being manufactured in rolls and it is advantageous not to require a compensating thickness stripe in the lower edge of the microfiche so that uniform rolling of the striped product results it will be found necessary to maintain the header stripe at a thickness below about 0.] mil.

Thus, in the successful practice of the invention any combination of layer thicknesses and pigment concentrations may be used within the above specified limits to achieve the required maximum 0.3 optical density and the required diffusion.

Although, as already described, a wide variety of film base, pigment and binder materials, concentrations thereof and layer thickness can be used to obtain a product of the type described broadly herein, a specifically preferred embodiment of the present invention utilizes a conventional diazo microfiche having a header region stripe about one-half inch wide coated on the surface opposite that which bears the diazo emulsion with a 0.09 mil thick layer comprising 40 percent by weight of zinc oxide in a polyamide binder produced by the condensation of dilinoleic acid and ethylene diamine as described above. Such a layer of pigment and binder is obtained by flexographic coating a 0.20 mil thickness of a solution comprising 30 percent by weight of said prepared polyamide resin, 20 percent by weight of zinc oxide, 2.5 percent by weight of water to improve solubility and the balance N- propyl alcohol. When such a solution is dried using conventional hot air techniques, a 0.09 mil thick layer of the pigmentbinder combination having an optical density of 0.l8 is left deposited on the microfiche. Up to 10th generation copies of such a microfiche made using conventional reproductive techniques (i.e., by the application of mercury vapor light) demonstrate little or no adverse effect upon the clarity of reproduction in the header region.

As should be clear, a film-base element having at least a stripe of a thin layer of the type described herein coated on one side thereof may be prepared for subsequent coating with any type of photosensitive emulsion. In the case of the microfiche described herein, the emulsion would of course be of the diazo type, however, a variety of applications might require the application of a more conventional silver halide or other type of emulsion.

Thus, the present invention provides a highly improved microfiche which provides for easy application of identifiers in the header region while concurrently providing for relatively problem-free reproduction of the header area in subsequent generation copies. There is also described a film base element suitable for the reception of a diazo or other photosensitive element which has coated at leastin a stripe on at least one side thereof a thin layer suitable for the reception of eyeball readable identifiers or to permit easy eyeball reading .of identifiers incorporated in an emulsion layer coated in the header region.

Theinvention has been described in detail with particular reference to specific embodiments thereof, however, it should be understood that variations and modifications can be made within the spirit and scope of the invention and that the same is to be limited only as described in the appended claims.

I claim:

1. An improved microfiche comprising a transparent base of 5 relatively great area having a header region of relatively much smaller area for the incorporation of identifiers, a photosensitive emulsion coated on the entire surface of one side of said base, and only in said header region a thin layer on the opposite side of said base comprising particles of inorganic pigment having a refractive index of from about 1.6 to about 2.1 dispersed in a polymeric binder, said thin layer being translucent to visible light, and substantially transparent to photographically active radiation thereby permitting eyeball reading of identifiers in the header region and conventional reproduction of the entire microfiche including the header region, wherein said thin layer has an optical density below about 0.3, wherein said thin layer comprises from about to about 80 percent by weight of said polymeric binder and from about 20 to about 80 percent by weight of said pigment, and wherein the thickness of said thin layer varies from about 0.03 to about 0.2 mil.

2. The microfiche of claim 1, wherein said photosensitive emulsion is selected from the group consisting of diazo and silver halide emulsions.

3. The microfiche of claim 1 wherein said pigment is selected from the group consisting of barium sulfate, zinc oxide and Lithopone.

4. The microfiche of claim 1 wherein said polymeric binder is selected from the group consisting of cellulose nitrate, cellulose acetate, cellulose acetate butyrate, acryloids, polyester resins, vinyl resins, rosin, rosin derivatives, epoxy resins, polyamide resins, and mixtures thereof and said thin layer has an optical density below about 0.2.

5. The microfiche of claim 1 wherein said base comprises a material selected from the group consisting of polyester, cellulose ester, polyolefin, polyamide and polycarbonate materials.

6. The microfiche of claim 5 wherein said base comprises a material selected from the group consisting of cellulose acetate, cellulose acetate butyrate, and poly(ethylene terephthalate). 

2. The microfiche of claim 1, wherein said photosensitive emulsion is selected from the group consisting of diazo and silver halide emulsions.
 3. The microfiche of claim 1 wherein said pigment is selected from the group consisting of barium sulfate, zinc oxide and Lithopone.
 4. The microfiche of claim 1 wherein said polymeric binder is selected from the group consisting oF cellulose nitrate, cellulose acetate, cellulose acetate butyrate, acryloids, polyester resins, vinyl resins, rosin, rosin derivatives, epoxy resins, polyamide resins, and mixtures thereof and said thin layer has an optical density below about 0.2.
 5. The microfiche of claim 1 wherein said base comprises a material selected from the group consisting of polyester, cellulose ester, polyolefin, polyamide and polycarbonate materials.
 6. The microfiche of claim 5 wherein said base comprises a material selected from the group consisting of cellulose acetate, cellulose acetate butyrate, and poly(ethylene terephthalate). 